Clutch



1953 D. E. HENDRICKSON ETAL 2,

cwrcn Filed Sept. 24, 1948 2 Sheets-Sheet 1 1953 0. E. HENDRICKSON EI'AL 2,661,826

CLUTCH Filed Sept. 24. 1948 2 Sheets-Sheet 2 Patented Dec. 8, 1953 CLUTCH Donald E. Hendrlckson, Edwin B. Doyle, and

Daniel M. Schwarts, Salt Lake City, Utah, asslgnors to The Eimco Corporation, Salt Lake City, Utah, a corporation of Utah Application December 24, 1948, Serial No. 87,172

18 Claims. I

This invention relates to clutches and more particularly to mechanically operated friction clutches for transmitting power from a driving member to a driven member.

An object of the invention is to provide a clutch having improved means for adjusting the clutch actuating parts to compensate for wear, Particularly wear in the friction elements of the clutch.

Another object is to provide a clutch having a positively acting and reliable actuating mechanism.

Another object is to provide a clutchincludlng a presser plate having a springy or resilient section providing automatic compensation for plate wear within limited ranges.

Another object is to provide a clutch wherein thrust is applied to the presser plate through a universal bearing insuring uniform application of actuating force to the friction elements of the clutch.

A further object is to provide in a clutch of this type adjustable means for applying pressure to the clutch elements through a presser plate including resilient means for returning the presser plate to normal position.

These and other objects and advantages, as will appear as the description proceeds, are achieved in a clutch including a rotary driving member, a rotary driven member coaxially positioned with respect to said driving member, and complementary clutch elements carried by said driving and driven members engageable and disengageable in the axial direction, a reaction plate mounted on one of said rotary members and adjustably positioned thereon. a presser plate, means mounting said presser plate on said reaction plate for axial movement to actuate said complementary clutch elements, clutch actuating means acting between said reaction plate and said presser plate to move said presser plate axially from normal position to a clutch-actuating position and resilient means urging said presser plate axially towards said normal position.

In the drawing, in which like reference numerals designate corresponding parts in the several views,

Fig. l is an axial sectional view of a clutch in accordance with the invention;

Fig. 2 is a sectional view taken along the plane of the line 22 of Fig. 1; and

Fig. 3 is a developed sectional view of plate taken along the circle I of Fig. 2.

Reierring now to'the drawing, the clutch shown has a driving shaft ill, conventionally journalled in bearings (not shown) at the left. Surroundthe cam ing the right hand end of the shaft II is a drum l I having a cylindrical drum face it coaxial with the shaft. The drum may be lournalled on the shaft II by a conventional bearing (not shown) that is secured to the drum by cap screws II and dowel ll. A grease seal it is included between the drum ll andthe shaft ill.

The end of shaft it is tapered at Iii and mounts a hub ll that is retained on the shaft by a nut ll threaded to the end of the shaft. The hub may be keyed to the shaft in the usual way. Circumferentially disposed about the periphery of the hub are a plurality of longitudinal splines ll supporting the driving clutch plates 20 that are notched at 21 to flt over the splines oi the hub. It will be seen that the clutch plates 20 are free to slide longitudinally of the hub and are constrained by the spline-notch connection to rotate with the hub. Clutch lining rings 1! are :gstened to the faces of the clutch plates by rivets The interior or the drum is also provided with circumferentially spaced inwardly projecting splines 24 that carry a plurality of driven clutch plates 26 interspaced between the driving clutch plates 20 in the usual complementary arrangement. The driven plates are notched at It so that they may be moved axially of the drum but cannot rotate with respect thereto.

Also mounted on the drum splines it by notched connections 21 is a presser plate II. This plate has a peripheral annular zone I! that bears against the right hand end of the stacked arrangement of clutch plates for exerting clutch engaging pressure thereon. By virtue of the notched connections 21. the presser plate rotates with the drum yet is free for axial movement therein.

Adjacent the presser plate, and to the right thereof as seen in the Fig. 1, is an adjusting plate or reaction plate 30. The adjusting plate has a peripheral threaded portion ll engaging corresponding internal threads 32 in the drum H. At the interface it between the drum Ii and the adjusting plate. a close machined fit is provided to pilot the plate in the drum; by this expedient. the threads "-32 may fit loosely to permit easy turning 01' the reaction plate in the drum while .insuring correct alignment of the parts.- A

spring-pressed locking pin II is mounted in the reaction plate and engages any one of a pinrality oi complementary holes SI in the presser plate II to lock the reaction plate in adjusted position.

As shown in Fig. l, the presser plate It has a aseasas 3 flanged portion It that extends into a recess in the reaction plate II to provide a clutch actuator cavity 31. Grease packing l4 seals the Joint between the presser plate and the reaction plate.

Within the cavity 81 is a clutch actuator including a cam plate 3! and cooperating follower assembly designated generally by the reference numeral 44.

Thefollowerassemblyhasahollowshaftll Journalledinadoubiethrustbearingfl. At the inner or cavity end of the hollow shaft is an integral spider 43 mounting follower rollers 44 on radial axes. There are three sets of rollers carriedbythespideronradialaxesspaced 120 apart.

Theradiallycamplate Itiscarried byashaftllthatpassesmitwardlyfromthe cavity Il through the bore ofthe hollow shaft 4|. The cam plate shaft is mounted for rotati'oninllintheboreofthehollow shaft. Thesebearlngspermitthecamplateshaft 4! to slide axially therein.

Cam plate 8! bears-against the presser plate Ilthroughauniversalthrustbearingdeviceineluding radially extending roller bearings 41 carriedbyacagellatoruslihavmgaspherical face 44, andacomplementary thrustring ll carrledbythepresserplate. Itwillbeseenthat t of'the cam plate to the left, as seen in Pig. 1, is to the presser plate throughtherollerbearingallthetomslland the thrust ring II. The spherical surface Iii permitathepraserplatetoawumeaposition delivering circumferentially equalized pressure to the bly of clutch elements II-II.

asmaybeseenml 'igs.2and3,thecamplate Ilhasthreeraisedlandsllfacingtherollers 44. The lamb are spaced 120' apart to correspond to the angular spacing of the rollers. Between the raised lands are dep areas I3. Theconnectingareasflmaybeuniformly sloped while the connecting areas I may be concavely formed, as best seen in Pig. 3.

It will thus be apparent that relative rotation of the cam plate and follower assembly will cause therollerstorideacrossthecarnplatesurfaces andtoforcethecamplatetotheleft,asseen in Fig. i, or permit itto return to the right. As showninFig Ltherolleraareontheraisedlands II and the cam plate is in full left hand position. Such relative rotation may be imparted to the clutch actuator parts by levers ii and 51 attached to the shafts 4| and 48 respectively. Of course, one of the levers may be fixed to a stationary member, and the clutch may be actuated by throwing the movable lever.

The mechanism for returning the presser plate to normal position when the follower rollers 44 are in depressions of the cam plate includes a slip-ring 4| rotatably retained on the flange ii of the presser plate by a split retaining ring ll received in a groove 84 formed in the flange 34. The slip ring carries a plurality of pins or studs 6|,speciilcally shown as three in number, that slidably extend through corresponding holes .2 in the adjusting plate 34. Springs BI surround the studs and are compressed between the adlusting plate and the lock-nuts 44 threaded on the endsofthepinstourgethepins,theslipring,and thepresserplatetotherlghttodisengage the clutch.

The slip-ring connectim between the presser plateandthespringpremedreturningmeans carried by the adjusting plate permits the adiustingplatetobescrewedlniioorqiit ll efi 4 drum while maintaining returning force on the presser plate. It is evident that when the adlusting plate is rotated in the drum, after releasing the lock pin 34, the studs and slip-ring rotate with the adjusting plate while the slip-ring rotates about the presser plate flange 36. In this manner, the presser plate, the adjusting plate and the actuator mechanism included therebetween may be moved longitudinally in the drum to a position in which correct pressure is applied to the clutch elements when the actuator mechanism is fully extended. As the friction discs of the clutch wear down in service, the adjusting plate may be moved inwardly of the drum to compensate for such wear.

Assembly and dbly of the clutch may be simply and expeditiously performed. As seen in Fig. i, all of the parts may be removed to the right. The out ii! is unscrewed for the removal of the lever ll. The lock-pin H is released, and the entire sub-assembly including the presser plate, the actuator and the adjusting plate may be unscrewed and removed from the drum. This sub-assembly may be dismantled by removing the lock-nuts 84 and separating the parts. With this sub-assembly removed from the drum, the clutch elements 20-48 may be withdrawn from their splined supports. The hub Il may be removed after unscrewing the nut l8. Removal of cap screws it will then permit the drum itself to be drawn to the right ofl theshaft Ill. The parts may be reassembled in the reverse order.

Operation of the clutch should be evident in the light of the foregoing description. In brief. however, it may be pointed out that with the clutch engaged, as shown in Fig. 1, power is transmitted from the driving shaft in through the hub I1, and through the clutch elements n45 to the drum. The parts that rotate with the drum include the presser plate 28 and the reaction plate 30. It is to be noted particularly that the actuator mechanism including the cam plate, the follower device and their shafts do not rotate with the drum; instead, these parts are relatively stationary. The adjusting plate rotates about the hollow shaft 4| on hearing 42 and the presser plate rotates relatively to the cam plate 39 on roller bearings 41.

when the clutch is disengaged, only the driving shaft II and its hub and clutch elements rotate. The remaining parts of the structure are stationary.

It is also to be noted that the presser plate has a relatively thin annular zone 8' between the universal thrust bearing and the annular zone 29 wherefrom pressure is applied to the clutch elements. Such thin zone is relatively resilient and permits the presser plate to bend somewhat when the clutch is engaged, thus applying a resilient pressure to the clutch elements. Small amounts of wear in the clutch discs is automatically compensated by the resiliency of the presser plate. Larger amounts of wear are corrected by adjusting the reaction plate, as explained hereinbefore.

Referring to the clutch actuating mechanism, the cam rise 54 preferably has a uniform slope making sharp angles with the lands I! and depressed areas 83. Thus, a uniform mechanical advantage between the operating levers II and I1 and the presser plate 28 is obtained. By this means, the operator is able to accurately Judge by feel the status of adjustment of the clutch and to make changes in the adI-ustment when necessary. Moreover, this uniform mechanical the clutch. This is of advantage where two' clutches are to be operated from the same lever; then, one clutch can be disengaged without dlsengaging the other.

An important advantage oi the present clutch is that adjustment oi the clutch does not affect the positions 01' the operating levers. Therefore, only a single adjustment need be made and no compensating adjustment of the operating levers is necessary. Moreover, adjustment of the clutch does not aflect the setting of the release springs 03.

From the foregoing description it is seen that the present invention provides a compact and eilicient clutch having adjusting means that permits long use of the clutch without requiring replacement of the friction elements. Adjustment is quickly accomplished without the use of tools and without requiring the removal of any parts. The clutch elements may be easily removed and replaced when so badly worn as to require such action. The presser plate of the clutch is biased to disengaging position by resilient means coacting with the reaction plate yet not interiering with the adjustability oi the latter.

It will be evident that various modifications may be made in the construction of the exemplary clutch herein shown and described without departing from the'invention. For example, the presser plate need not be splined to the drum; instead, it may be carried solely by the reaction plate, in which case, the reaction plate is locked in its adjusted position directly to the drum. Such modified form of clutch retains the advantages oi the clutch actuating device and plate sub-assembly.

We claim:

1. In a clutch including a rotary driving member, a rotary driven member coaxially positioned with respect to said driving member, and complegnentary clutch elements carried by said driving and driven members engageable and disengageable in the axial direction, a reaction plate mounted on one of said rotary members and adjustably positioned thereon, a presser plate, means mounting said presser plate on one of said rotary members for axial movement to actuate said complementary clutch elements, clutch actuating means acting between said reaction plate and said presser plate to move said presser plate axially away from said reaction plate to a clutchactuating position, and resilient means acting between said reaction plate and said presser plate urging said presser plate axially towards said normal position.

2. In a clutch including a rotary driving member, a rotary driven member coaxially positioned with respect to said driving member, and complementary clutch elements carried by said driving and driven members engageable and disengageable in the axial direction, a reaction plate. complementary screw thread means mounting said reaction plate on one of said rotary members for axial adjustment with respect thereto, a

presser plate. means mounting said presser plate on one of said rotary members for axial movement to actuate said complementary clutch elements, clutch actuating means acting between said reaction plate and said presser plate to move said presser plate axially away irom said reaction plate to a clutch-actuating position, and resilient means acting between said reaction plate and said presser plate urging said presser plate axially towards said normal position.

3. In a clutch including a rotary driving member, a rotary driven member coaxially positioned with respect to said driving member, and complementary clutch elements carried by said driving and driven members engageable and disengageable in the axial direction, a reaction plate. complementary screw thread means mounting said reaction plate on one oisaid rotary members for axial adjustment with respect, thereto, a presser plate, means mounting said presser plate on said one rotary member for rotation therewith and ior axial movement therealong, a slip-ring rotatably mounted on one of said plates, means holding said slip-ring for rotation with the other or said plates, clutch actuating means acting between said reaction plate and said presser plate to move said presser plate axially from normal position to a clutch actuating position, and spring means urging said 1piresser plate axially towards said normal posi- 4. In a clutch including a rotary driving member, a rotary driven member coaxialiy positioned with respect to said driving member, and complementary clutch elements carried by said driving and driven members engageable and disengageable in the axial direction, a reaction plate, complementary screw thread means mounting said reaction plate on one of said rotary members for axial adjustment with respect thereto, a presser plate, means mounting said presser plate on said one rotary member for rotation therewith and for axial movement therealong, a slip-ring rotatably mounted on said presser plate, means holding said slip-ring for rotation with said reaction plate, clutch actuating means acting between said reaction plate and said presser plate to move said presser plate axially from normal position to a clutch actuating position, and spring means urging said presser plate axially towards said normal position.

5. In a clutch including a rotary driving member, a rotary driven member coaxially positioned with respect to said driving member, and complementary clutch elements carried by said driving and driven members engagable and disengagable in the axial direction, a reaction plate mounted on one of said rotary members, a presser plate, means mounting said presser plate on one of said rotary members for axial movement to actuate said complementary clutch elements, clutch actuating means including a substantially non-rotating cam and iollower device acting between said reaction plate and said presser plate to move said presser plate axially away from said reaction plate to a clutch-actuating position, and resilient means acting between said reaction plate and said presser plate urging said presser plate axially towards said normal position.

6. In a clutch including a rotary driving member, a rotary driven member coaxially positioned with respect to 'said driving member. and complementary clutch elements carried by said driving and driven members engageable and disengageable in the axial direction, a presser plate, means mounting said presser plate on one of said rotary members for axial movement away from said reaction plate to actuate said complementary clutch elements, clutch actuating means urging said presser plate from normal position to clutch actuating position, and resilient means urging said presser plate axially towards said normal position, said presser plate having a resilient zone between the point at which said clutch actuating means acts thereon and the area from which actuating force is applied to the complementary clutch elements.

7. A clutch as defined in claim 1 having means for locking said reaction plate in adjusted position.

8. A clutch comprising a rotary shaft, a rotary drum coaxially surrounding an end of said shaft, an assembly of complementary friction rings carried by said shaft and said drum engageable and disengageable in the axial direction, a presser plate carried by said drum and mounted for axial movement therealong into and out of engagement with said assembly of friction rings, a reaction plate mounted on said drum adjacent to said presser plate, clutch actuating means acting between said presser plate and said reaction plate to move said presser plate axially into engagement with said assembly of friction rings, means for adjusting the axial position of said reaction plate with respect to said drum including a screw threaded connection mounting said reaction plate on said drum, and means for returning said presser plate to normal position including a slip-ring rotatably mounted on said presser plate and resilient means acting between said slip-ring and said reaction plate.

9. In a clutch including a rotary driving member, a rotary driven member coaxial with said driving member, and complementary clutch elements carried by said driving and .driven members engageable and disengageable in the axial direction; a reaction plate mounted on one of said rotary members and adjustably positioned thereon, a presser plate, means mounting said presser plate on one of said rotary members for axial movement to actuate said complementary clutch elements. clutch actuating means to move said presser plate from normal position to a clutch-actuating position, resilient means acting between said reaction plate and said presser plate urging said presser plate towards said normal position, and a slip-ring connection between said resilient means and one of said plates.

10. A clutch as defined in claim 9 wherein said resilient means is mounted between said slip-ring connection and said reaction plate.

11. In a clutch including a rotary driving member, a rotary driven member coaxially positioned with respect to said driving member, and complementary clutch elements carried by said driving and driven members engageable and disengageable in the axial direction, a reaction plate mounted on one of said rotary members, a presser plate, means mounting said presser plate on one of said rotary members for axial movement to actuate said complementary clutch elements, clutch actuating means acting between said reaction plate and said presser plate to move said presser plate axially away from said reaction plate to a clutch-actuating position, said clutch actuating means including a thrust type bearing means acting against said presser plate, and resilient means urging said-presser plate axially towards said normal position.

12. In a clutch including a rotary driving member, a rotary driven member maxially positioned with respect to said driving member, and complementary clutch elements carried by said driving and driven members engageable and discngageable in the axial direction, a reaction plate mounted on one of said rotary members, a presser plate, means mounting said presser plate on one of said rotary members for axial movement to actuate said complementary clutch elements, clutch actuating means including a substantially non-rotating cam and follower device acting between said reaction plate and said presser plate to move said presser plate axially away from said reaction plate from normal position to a clutch-actuating position, said cam and follower device being operable by relative rotation between the cam and follower, and resilient means urging said presser plate axially towards said normal position.

'13. In a clutch including a rotary driving member, a rotary driven member coaxially positioned with respect to said driving member, and complementary clutch elements carried by said driving and driven members engageable and disengageable in the axial direction, a reaction plate mounted on one of said rotary members, a presser plate, means mounting said presser plate on one of said rotary members for axial movement to actuate said complementary clutch elements, clutch actuating means acting between said reaction plate and said presser plate to move said presser plate axially from normal position to a clutch-actuating position, said clutch actuating means being journalled in at least one of said rotary members to allow rotation thereof relative to the clutch-actuating means, and resilient means urging said presser plate axially towards said normal position.

14. In a clutch as defined in claim 12, said cam and follower device having a dwell position where relative rotation between the cam and follower maintains the actuating position of the clutchactuating means.

15. In a clutch as defined in claim 12, said cam and follower device having a dwell position where relative rotation between the cam and follower maintains the disengaged position of the clutch actuating means.

16. In a clutch as defined in claim 12, said cam having rise portions of constant slope.

DONALD E. HENDRICKSON. EDWIN B. ROYLE. DANIEL M. SCHWARTZ.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,745,079 Conway Jan. 28, 1930 2,077,709 Pearmain Apr. 20, 1937 2,201,567 Walters May 21, 1940 FOREIGN PATENTS Number Country Date 362,568 Great Britain Dec. 10, 1931 

